Conventionally, in image processing apparatuses, operations using icons which enable excellent GUIs have been available. In recent years, these image processing apparatuses more and more deal wit data files of large volume such as images with their improvements in processing power. For example, Japanese Unexamined Patent Publication No. 19669/1994 (Tokukaihei 6-19669 published on Jan. 28, 1994) discloses a typical prior art operation method for processing data files of large volume. In this method, reduced-size images called “thumbnail” images, which allow a user to identify the contents of data files, are displayed, and using the reduced-size images as icons, a function as desired such as print, transmission, etc., is selected by performing a drag-and-drop operation on a reduced-size image directly, and the data file is processed with the selected function.
According to the foregoing method of processing data flies, it is possible for a user to ascertain the contents or intended use of the data files based on the reduced-size images without the need of opening each data file on the screen using application software, and therefore an improved operability can be achieved.
However, the foregoing conventional methods have presented the user with several difficulties when processing a large number of data files. For example, each icon of reduced-size image becomes too small and the image quality becomes too low for a user to see the details, and it is therefore difficult for the user to identify the contents of the original data file. In response, each icon of reduced-size image may be displayed in larger size. However, in this case, other problems arise. For example, all the icons of reduced-size images cannot be displayed at one time, or an icon may be positioned over some of the function icons while a drag-and-drop operation is being performed, which presents a user with difficulties in selecting a function icon as desired. Furthermore, when. adopting larger size icons of reduced-size images, a larger amount of data needs to be processed for a display in a drag operation.